Central mechanism of the organization for the visuo-motoer co-ordinations under the altered gravity environment

我们人类已经适应了地球上的重力环境，我们的运动行为由感觉系统支持，已经调整为重力特定形式。（Yves, Koga et al., 1993）在1G条件下，移动腿走路、用手指指向外面某处、将脖子转向声源、通过控制眼外肌肉用眼睛寻找某物等都是组织良好的。当人类暴露在重力条件改变的环境中时，这种程序化的行为必须改变；也就是说，它在重新编程。不寻常的诱导重力情况，如旋转、线性加速和平行摆动（Guedry, 1965, Lackner, 1977）也被研究过。许多研究者已经就视觉稳定性对视觉诱导的运动感觉或扭曲知觉进行了评估（Rock & Halper, 1968, Lackner & Ashton, 1981, Allison et al.1998, Howard, 1986, Yves, 1993, Young et al.1983，古贺，1992,1998,2000，Higashiya…More ma &古贺，1998,2002）。这些研究都是关于重力的影响和通过人的视觉感知诱发晕动病。在微重力下的直接研究，比如抛物线飞行，太空实验室。和太空实验室，已经进行了。（Young et al.1986）这些研究不仅关注人类在特定重力条件下如何通过各种感觉传入建立视觉稳定性，而且还与SAS （Space Adaptation Syndrome）有关。在我们日常生活中，在地球正常重力条件下，视觉、前庭和体感知觉的相互作用是顺利协调的。在微重力下保持我们健康生活的另一个困难应该在这里指出。空间适应综合征（Space Adaptation Syndrome，简称SAS）是人类在微重力环境下所遭受的一种疾病。包括人体轴在内的视觉环境在外心轴和自心轴上都发生了变化。当人体进入微重力环境时，重力改变引起的输入剧烈变化会引起非适应综合征，称为SAS。本章无意在这里详细描述这个主题，但应该考虑到整个人类在空间中的适应行为。少

We, human beings, have been adapted to the gravity environment on the earth and our motor behavior supported by sensory system has been tuned up for the gravity specific form. (Yves, Koga et al., 1993) Moving a leg to walk, pointing outside somewhere by the finger, turning a neck to the sound source, and looking for something with eyes by controlling extraocular muscles, are all well organized under the 1G condition. When humans are exposed to an environment with altered gravity conditions, this programmed behavior must be change ; that is, it is reprogramming. Unusual induced gravity situations, such as rotation, linear acceleration, and parallel swinging, (Guedry, 1965, Lackner, 1977) have also been investigated. Visually induced motion sensation or distorted perception has been evaluated with respect to visual stability by many investigators (Rock & Halper, 1968, Lackner & Ashton, 1981, Allison et al.1998, Howard, 1986, Yves, 1993, Young et al.1983, Koga, 1992, 1998, 2000, Higashiya … More ma & Koga, 1998, 2002). These studies are all concerned with the effect of gravity and the induction motion sickness through human visual perception. Direct investigations under microgravity, such as parabolic flight, Skylab., and Spacelab, have been conducted. (Young et al.1986) These studies not only focused on how human visual stability is established through various sensory afferent in specific gravity conditions but also related with the SAS (Space Adaptation Syndrome). The interaction of visual, vestibular and somatosensory perception is smoothly coordinated under the normal gravitational condition of Earth in our daily life. Another difficulty to keep our healthy life under the microgravity should be noted here. SAS(Space Adaptation Syndrome) is the one which human beings suffers under the micro-gravity environments. Visual environments including human body axis changed in both exocentric and egocentric axis. The acute change of input caused by altered gravity causes non-adaptive syndrome when human reaches micro-gravity environment which is called SAS. The chapter has no aim to describe the subject in detail here, but it should be taken into account to consider entire human adaptive behavior in space. Less